SVOA MATERIALS SCIENCE & TECHNOLOGY (ISSN: 2634-5331) Research Article https://sciencevolks.com/materials-science/ Volume 2 Issue 2 The Research and Development of Thermoplastic Elastomers HAN Jibin, CHEN Wenquan, ZHANG Shijia, WANG Yuan, Han Lili, Liu shuya, Tian Hongchi* Dawn Polymer CO., LTD, Thermoplastic Elastomer Branch of China Synthetic Rubber Industry Association, China Corresponding author：Tian Hongchi , Professor-level /Vice President/Chief Engineer, Shan Dong Dawn Polymer Co. Ltd, China, Tel:0086- 13964511068,13911727137. Received: May 15, 2020 Published: June 03, 2020 Abstract: In this article, the types, market overview, industrialization progress, and the latest research and development directions of chemically synthesized and blended thermoplastic elastomers were reviewed. Several new types of thermoplastic elas- tomers with market application prospects were introduced, such as silicone TPE, polyolefin TPE, bio-based TPE, degrada- ble TPE. Their performance and market development were discussed, and the application field and industrialization direc- tion were reviewed and prospected. Keywords: Thermoplastic elastomer; TPE; Industrialization development Introduction China's industrialized production of TPE began in the 1990s and China has been the world's largest TPE consumer after Thermoplastic elastomer (TPE) is a polymer material with more than 20 years of rapid development. the characteristics of thermoset vulcanized rubber and thermoplastic, which exhibits high elasticity of thermoset 1. Supply and demand of TPE in the global market: vulcanized rubber at room temperature and good pro- cessability of thermoplastic at high temperature. Due to The application fields of TPE are very extensive. It is the po- this special property, TPE is also called "third-generation tential replacement products of most rubber products and it can also be used for polymer modification. TPE can be blend- rubber" [1]. Because the vulcanization is not required and ed with various polymers such as polypropylene (PP), polyeth- the molding process is simple, the industrial production ylene (PE), polystyrene (PS). The blend shows excellent impact process of TPE is shortened by 25%, the energy consump- resistance, flexibility, and flexural properties, which is widely tion is saved by 25% to 40% and the efficiency is increased used in many fields like automotive, construction, electrical by 10 to 20 times compared with traditional thermoset appliances. With the fast development of China's auto indus- vulcanized rubber, which can be called another technolog- try and home appliance industry, the amount of TPE used in ical revolution in the rubber industry. What’s more, TPE polymer modification will grow rapidly. According to American can be processed and recycled for many times, saving the Freedonia Group data, the global TPE market exceeded $ 24 petroleum resources required for synthetic polymer mate- billion and market demand reached 6.7 million tons in 2019, rials and reducing environmental pollution [2,3]. At pre- which will grow at a rate of 5.2% each year in the future. Chi- sent, TPE is widely used in many industries such as auto- na’s TPE market consumption accounts for about 36% of the motive, construction, household equipment, wire and global total consumption and it is one of the fastest growing cable, electronic products, food packaging, medical equip- countries in the world. The average growth rate of the global ment. Under the background of increasingly scarce petro- TPE market is tending to moderate, the report said: This is leum resources and serious environmental pollution, TPE because the TPE market is gradually maturing. Asia and the Pacific will be the markets with the greatest demand for TPE has extremely important commercial value and environ- and demand for TPE in these two regions will grow at an mental protection significance, and it has become a re- above-average rate. In 2019, demand in these two-regions search hotspot in the field of polymer materials. In recent accounted for about 50% of global demand. Among them, years, continuous product innovation by TPE manufactur- China will be the world's largest consumer of TPE products, ers has promoted the development of the downstream and the annual market demand growth rate is close to 8% application market. They have replaced traditional syn- while the growth rate in the European and North American thetic rubber in different application fields, and their ap- markets is slowing down and the growth rate in other parts of plications have grown significantly. the world is more moderate. 34 SVOA Materials Science and Technology “The Research and Development of Thermoplastic Elastomers” 2. Development status of various thermoplastic elasto- The third-ranked waterproof membrane accounts for about mers 15 %; The adhesive market accounts for about 13% of total consumption. It is expected that SBS consumption will grow After years of development, TPE has formed more than 30 at an average annual rate of 3.5% in the future. The SBC con- varieties in 10 categories. The main varieties of TPE are ther- sumption of developed countries such as the United States, moplastic styrene elastomer (SBC or TPS), thermoplastic poly- Western Europe and Japan will grow more slowly in the fu- olefin elastomer (TPO), thermoplastic polyurethane elasto- ture due to the relatively mature markets, and the Asia- mer (TPU), thermoplastic polyester elastomer (TPEE), thermo- Pacific region will become a new round of development cen- plastic polyamide elastomer (TPAE), thermoplastic vulcanizate ter for SBS. In recent years, the demand for the SBS market (TPV), organo-fluorine elastomer (TPF), organic silicones, etc., has shrunk, and the proportion of consumption has de- covering almost all fields of synthetic rubber and synthetic creased year by year. The development direction is SEBS, SIS resin. In recent years, many new varieties of TPE have been and high-end SBS products. At present, the proportion of SBS developed by researchers to meet some special needs of us- in SBC product consumption structure is as high as 95% while ers, such as high temperature resistance, heat oil resistance, SEBS and SIS only account for 5% in China, far lower than high barrier properties, high insulation. developed countries such as the United States and Japan. This is because Chinese SBC mainly focuses on low-end prod- 2.1 Styrenic block copolymer TPE (SBC) ucts, while many high-end products such as SEBS and SEPS mainly rely on imports compared with countries besides Chi- Styrene-based thermoplastic elastomers are ABA-type na. triblock copolymers. The remarkable structural features are that some chemically different plastic segments (hard seg- ments) and rubber segments (soft segments) are connected or grafted in series between polymer chains to form a mi- crophase separation structure and the hard segments are Adhesive 13% dispersed in the soft elastic matrix, which enhances the creep Polymer modification 19% resistance, while the soft rubber matrix provides elasticity so Asphalt modification 19% Waterproof materials that the temperature range of TPEs can be from the low Tg of 15% the soft segment to the high Tg of the hard segment [4,5 ]. At Shoe material 34% present, the SBC is the largest production of thermoplastic elastomer with the closest performance to rubber. SBC series products include styrene-butadiene block copolymer (SBS), styrene-isoprene block copolymer (SIS) and styrene-isoprene- butadiene block copolymer (SIBS), and the corresponding hydrogenated copolymers are SEBS, SEPS, SEEPS. SEBS is the most common type of hydrogenated styrene block copoly- mer. Compared with SEBS, SEEPS have higher tensile Figure 1. The proportion of global SBC consumer markets strength, better oil filling performance, smoother surface and 2.1.2 The development trends of SBC better low temperature performance [4,5]. SBS has the larg- est output, accounting for more than 70% of SBC consump- SEBS is a widely studied thermoplastic triblock copolymer tion; SIS roughly accounts for 20% of SBC consumption, and [8,9]. SEBS was firstly industrialized by the US Shell company SEBS-based hydrogenation products account for about 7% of in 1972, and the equipment and technology were inherited SBC consumption. by the US Kraton company. Due to the excellent perfor- mance and a wide range of applications of SEBS, there are 2.1.1 Development of market application of SBC prod- currently many companies engaged in the production and R ucts & D of SEBS, like Kraton Company of the United States, Asahi Kasei Corp. of Japan, Kuraray and JSR, Eni Chem of Italy, The application of SBC series products and its market capaci- Repsol of Spain, TSRC Corporation, Formosa Plastics Corpora- ty: In 2017, the global production capacity of SBC was 2793kt, tion, LCY Chemical Corp., and Baling Petrochemical, Sinopec of which China was 1230kt, accounting for 44% of the world. Group, TSRC (Nantong) Company, Zhejiang KEYUAN Petro- In 2018, SBC production capacity increased to 1395kt, and the chemicals Company. At present, the total production capaci- output reached 1081kt in China [6]. Since SBC entered com- ty of SEBS in the world is close to 500,000 tons / year and in mercialization in the 1960s, SBS has been one of the most China is about 150,000 tons / year, and there are also manu- successful commercial products in history [7]. The total pro- facturers who are actively planning to build devices. The duction capacity of SBS in the world accounts for 80% of the range of application SEBS is very wide, such as auto parts, total production capacity of SBC. Shoemaking is still the larg- children's toys. [10]. SEPS is industrialized by American Kra- ton and Japan Kuraray Corporation while China Baling Petro- est consumer market for SBS, accounting for about 34% of chemical realized industrialization in August 2017, and SEEPS the total consumption; followed by the asphalt modifier and is only produced by Japan Kuraray Corporation. polymer modifier market, accounting for about 19%; 35 SVOA Materials Science and Technology “The Research and Development of Thermoplastic Elastomers” 2.1.2.1 Research progress of hydrogenated SBC Mishra et al.